Flash cache on one server can be shared across a cluster with the company's software

PernixData, a startup founded by VMware veterans, says its software can turn server-based flash storage into a resource shared across a standard VMware cluster of as many as 32 systems.

Making that cache available across a whole cluster will let enterprises scale out their storage capacity with consistently fast access to data, according to co-founder and CEO Poojan Kumar, who previously managed VMware's data products. PernixData's product, called PernixData FVP (Flash Virtualization Platform), works without modifications to the hypervisor or applications and is designed to coexist with SANs (storage area networks), he said.

Putting flash storage directly into servers is a growing solution to the need for faster access to data, but the technology's been limited to individual servers, so virtualized environments can't fully take advantage of it, according to PernixData. Clusters of virtualized servers typically share data over a SAN, which can raise performance problems, Kumar said. Multiple network hops and contention over a shared SAN link can all slow down access to the data that applications need.

PernixData's software can turn flash cards on all the servers in a virtualized cluster into a shared cache, which serves as a tier of storage above a SAN for the most-used data. It's a software-only product and can use on-server flash that customers already have deployed. Announced on Tuesday, PernixData FVP is available immediately for $7,500 per host for an enterprise package. It's initially for VMware environments, though ultimately it will work with multiple hypervisors, including KVM and Microsoft's Hyper-V, Kumar said.

The software is designed to allow fast access to data while virtualizing server resources. The virtual machines on a given server mostly will get their data from the cache right on that system. But even when they need to tap into another server on the cluster, that will be faster than going out to a SAN, the company said: Delays can be measured in microseconds rather than milliseconds. And PernixData works with all features of VMware, such as movements of VMs using VMotion, making management easier, Kumar said.

Another advantage to PernixData's approach is that administrators can control which VMs can use which flash resources, giving preference to the jobs that most need the performance. It does this by taking advantage of both the VM and the storage being on the cluster, so that kind of control isn't possible with flash that's on a SAN, Kumar said.

VDI should cut maintenance and energy costs while helping ensure security and giving workers more flexibility, said Jason Rolla, chief technology officer. For example, doctors frequently move between their offices and examination rooms, he said. "Technically, they could carry their office everywhere they went," Rolla said.

CRHPC has an almost four-year-old Dell EqualLogic storage array in its headquarters data center that's connected to its servers via iSCSI. But when it tried to set up VDI using just the array for storage, application response times were much longer than the 3 milliseconds that CRHPC was aiming for, Rolla said.

Tests with 10 virtual desktops showed that using the cache with PernixData will cut down on response time by about three-quarters, and CRHPC now plans to implement the software in its full VDI rollout, Rolla said.

PernixData should be useful for databases and big data analytics, as well as VDI, said Gartner analyst Chris Wolf. Virtualized storage products from some other vendors, including VMware, have been hard to sell because they were too expensive for what they did, he said.

"As long as the product holds up to what it appears to do on paper, Pernix is going to put a lot of price pressure on some of the more industry heavyweights here," Wolf said.